#1 If you don't have the curse client already then get it. You can download it here:

http://www.curse.com/client/

Follow the installation instructions they are on the same web page as the download link I provided.

#2 Once Curse is up and running correctly get the addon called Gatherer. Gatherer is awesome for both Mining and Herbalism. It will mark on the maps for each area any location where an attempted mining of an ore occurred or anywhere that a successfully mined ore was mined by yourself or anyone in your guild. It records the type of ore and any other things gathered such as gems etc. and the records will be there for any of your characters that have the mining skill. It does the same for Herbalism and any herbs gathered.

#3 After you have installed the Curse client and the Gatherer addon and after mining an area several times you will have built up a fairly decent database of where ores are usually found. You can rest assured that the ores will generally always reappear in the same clustered areas (not in the same exact spots just the general area.) So you don't have to waste too much time searching for their locations just head right to where the clustered marked locations are and voila you will find ore. Very fast and effective, I've made an average of 700gp in 6 hours with Gatherer mining in Northrend.

Good luck and have fun